U.S. patent application number 12/897809 was filed with the patent office on 2011-04-07 for system, apparatus and method for maintaining airway patency and pressure support ventilation.
Invention is credited to Richard J. Arnott.
Application Number | 20110079224 12/897809 |
Document ID | / |
Family ID | 43822209 |
Filed Date | 2011-04-07 |
United States Patent
Application |
20110079224 |
Kind Code |
A1 |
Arnott; Richard J. |
April 7, 2011 |
System, apparatus and method for maintaining airway patency and
pressure support ventilation
Abstract
An assembly for modifying airflow into a nasopharyngeal airway
or trachea of a patient. A valve assembly having an inlet and an
outlet attaches to a traditional airflow generator. A valve seal
within the assembly is operable by a solenoid and is adapted to
cycle in response to a programmable controller circuit wherein upon
activation of both the airflow generator and the controller
circuit, pressurized air from the airflow generator continuously
enters the inlet but passes out of the outlet of the assembly only
when the solenoid causes the valve seal to retract and to at least
partially unblock the outlet such that the pressurized air is
converted into a single, repeatable burst exiting the outlet
thereby modifying the traditional airflow.
Inventors: |
Arnott; Richard J.;
(Pittsburgh, PA) |
Family ID: |
43822209 |
Appl. No.: |
12/897809 |
Filed: |
October 5, 2010 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61249323 |
Oct 7, 2009 |
|
|
|
61258257 |
Nov 5, 2009 |
|
|
|
Current U.S.
Class: |
128/204.21 ;
128/205.24 |
Current CPC
Class: |
A61M 15/00 20130101;
A61M 16/204 20140204; A61M 16/0816 20130101; A61M 2016/0024
20130101; A61M 16/021 20170801; A61M 16/20 20130101; A61M 16/0066
20130101 |
Class at
Publication: |
128/204.21 ;
128/205.24 |
International
Class: |
A61M 16/20 20060101
A61M016/20; A61M 16/00 20060101 A61M016/00 |
Claims
1. An assembly for modifying airflow into a nasopharyngeal airway
or trachea of a patient, comprising: a valve assembly adapted to
attach to an airflow generator, said valve assembly having two
ends, an inlet and an outlet defined between each of said ends, and
an interior feed tube, said valve assembly further comprising: a
motor means disposed at one of said ends; an exit tube defined at
the other of said ends; a valve seal within said interior feed tube
connected to and operable by said motor means, said valve seal
adapted to cycle within said interior feed tube between said motor
means and said exit tube and across said outlet; a controller
circuit connecting to said motor means for operating said motor
means incrementally; and, wherein upon activation of both said
airflow generator and said controller circuit, pressurized air from
said airflow generator continuously enters said interior feed tube
from said inlet but passes out of said outlet only when said motor
means causes said valve seal to move in relation to said exit tube
to at least partially unblock said outlet such that said
pressurized air is converted into a single, repeatable burst
exiting said outlet.
2. The assembly of claim 1, wherein said valve seal is a shaped
member which seals against an inside surface of said interior feed
tube.
3. The assembly of claim 1, wherein said valve seal is a sliding
tube valve seal including a tube and having defined therein at
least one slot and further including an internal wall positioned
beyond said slot adapted to direct said single, repeatable burst
through said slots and out of said outlet when said tube is moved
by said motor means.
4. The assembly of claim 1, further comprising a return spring
attached to said motor means for returning said valve seal to a
rest position downstream from said outlet.
5. The assembly of claim 4, wherein said spring is attached solely
to said motor means at an end thereof.
6. The assembly of claim 4, wherein said spring is positioned
between said motor means and said valve seal.
7. The assembly of claim 6, wherein ventilation holes are defined
through said interior feed tube beyond said outlet and in front of
said motor means.
8. The assembly of claim 1, further comprising a drug delivery port
connected to said inlet through which said pressurized air passes
and into which an inhalable medication can be received.
9. The assembly of claim 1, wherein said valve assembly further
includes a plunger rod extending said valve seal from said motor
means.
10. The assembly of claim 1, further comprising a normally-open
electrical switch connected to said outlet and to said controller
circuit for charging said motor means.
11. The assembly of claim 10, further comprising a patient
interface device connected to said switch for receiving said
repeatable burst from said outlet.
12. The assembly of claim 1, further comprising a programmer linked
to and encoding said controller circuit for adjusting said single,
repeatable burst.
13. An assembly for modifying airflow into a nasopharyngeal airway
or trachea of a patient, comprising: means for producing a constant
head of pressurized airflow into a valve assembly attached to a
patient, said valve assembly including a solenoid-operated valve
seal; means for maintaining said airflow against said valve
assembly while said patient is exhaling and said valve seal is at
rest; and, means for permitting said valve seal to incrementally
retract and allow said airflow to pass through said valve assembly
and into said nasopharyngeal airway or trachea when said patient
inhales, as a result converting said constant head of pressurized
airflow into an assisted burst of gas given during inhalation while
allowing said patient to finish inspiration and exhale against
little or no pressure when said valve seal is at rest.
14. The assembly of claim 13, further comprising a means for
adjusting said assisted burst.
15. The assembly of claim 13, further comprising a means for
delivering medication to said patient when said patient
inhales.
16. The assembly of claim 13, further comprising a means for
allowing said patient to intake ambient air when said valve seal is
at rest.
17. A method for modifying airflow into a nasopharyngeal airway or
trachea of a patient, comprising the steps of: attaching a valve
assembly to an airflow generator, said airflow generator producing
a constant head of pressurized airflow into said valve assembly,
said valve assembly including a solenoid-operated valve seal;
attaching said valve assembly to a patient; maintaining said
airflow against said valve while said patient is exhaling and said
valve is at rest; and, permitting said valve seal to incrementally
retract and allow said airflow to pass through said valve assembly
and into said nasopharyngeal airway or trachea when said patient
inhales, as a result converting said constant head of pressurized
airflow into an assisted burst of gas given during inhalation while
allowing said patient to finish inspiration and exhale against
lower or no pressure when said valve seal is at rest.
18. The method of claim 17, further comprising the step of
adjusting said assisted burst.
19. The method of claim 17, further comprising the step of
delivering medication to said patient when said patient
inhales.
20. The method of claim 17, further comprising the step of allowing
said patient to intake ambient air when said valve is at rest.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The instant application claims benefit of provisional
application Ser. No. 61/249,323 filed Oct. 7, 2009 and provisional
application Ser. No. 61/258,257 filed Nov. 5, 2009, the disclosures
of both of which are incorporated herein by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The invention relates to the modification of pre-existing
airflow generation means to produce a pressurized airflow burst or
flow of air directed into the nasopharyngeal airway or trachea of
the patient as a patient's inhalation action continues or is caused
to occur.
[0004] 2. Description of the Related Art
[0005] Breathing disorders or respiratory related problems widely
exist for conditions such as sleep apnea, ventilation support,
pharmaceutical delivery systems, and manual resuscitation. Each of
these conditions requires a system, method and apparatus for
treatment. Several of these markets are sustained today by a
related line of products each having one thing in common, namely
pressurized ventilation support referred to as Positive Airway
Pressure (PAP). In most cases conditions are treated by a
continuous positive pressure air source or a continuous positive
pressure gas source. At times there may be variations such as a
bi-level positive pressure air or gas source delivered by a self
contained product for comfort. Unfortunately there are several
circumstances where a continuous positive pressure air or gas
source is not comfortable, reasonable or useful and a standard
bi-level product is cost prohibitive.
[0006] In the case of Obstructive Sleep Apnea or OSA, the gold
standard remains to be a continuous positive pressure of air, which
is uncomfortable to say the least. Many patients cannot tolerate
the application of continuous positive airway pressure,
particularly because of the discomfort associated with exhalation
against a continuous positive pressure or the dryness that
accompanies this type of delivery. A solution has been developed to
alleviate this problem by the addition of a method and apparatus,
to an existing continuous positive pressure of air, which converts
a substantially constant elevated airway pressure to the patient's
airway, with periodic short term reductions of the elevated airway
pressure to a pressure of lesser magnitude. A further advance in
such treatment involves the application of alternative high and
low-level positive airway pressure wherein the low-level pressure
coincides with the breath exhalation of the patient's breathing
cycle.
[0007] Although more expensive devices may be available that
provide relief upon exhalation, they are cost-prohibitive, designed
for a single use and tightly regulated by insurance companies. In
some cases no device is available at all. By providing a limited
reuse/disposable add on or in some cases a durable add on
regulating device, the cost, hygiene and comfort for these patients
become palatable.
[0008] In addition, when different drugs, including oxygen, are
delivered to a patient via continuous pressure the drug amount is
difficult to regulate because breathing rates differ from patient
to patient. Take the case of a comatose or mentally handicapped
patient. Coordinating inhalation of drug delivery with the
breathing cycle is impossible. Yet, with a bi-level attachment to
oxygen or a continuous air delivery system, an appropriate
treatment amount is delivered and waste is minimized.
[0009] There are several bi-level apparatus devices available. Each
has a specific use and is self-contained. Some are manually
manipulated. However, there is no method or device that can be
added to an existing continuous positive air or gas source which
will convert them for the application and delivery of bi-level
positive airway pressure to a patient.
[0010] The systems, methods and apparatus disclosed in the prior
art for treating patients afflicted with such maladies as sleep
apnea, snoring, ventilation support and pharmaceutical delivery
present a number of problems which need to be addressed. The
equipment utilized in such treatment is far too limiting. In the
case of sleep apnea, the air stream delivered to the patient tends
to dehydrate the nasopharyngeal tissue. The unnatural sensation and
discomfort experienced by the patient in overcoming the positive
pressure during exhalation results in many patients abandoning the
use of a system that is in all other respects quite beneficial. An
alternative, much more expensive device is rejected by many
insurance companies. By supplying a device as a simple add-on
product it is possible to convert these devices to a comfortable
useful source of treatment, as follows.
SUMMARY
[0011] It is the objective of the instant invention to provide a
device which may be added to any continuous positive air pressure
(CPAP) or gas source be it in the home, hospital or via emergency
medical treatment.
[0012] It is further the objective of the invention to lessen the
unnatural sensation and discomfort experienced by the patient in
overcoming the traditional positive pressure during breath
exhalation.
[0013] It is further the objective of the invention to supply the
device as a simple add-on product to convert these traditional CPAP
units to a useful source of treatment without considerable
expense.
[0014] Accordingly, what is provided is an assembly for modifying
airflow into a nasopharyngeal airway or trachea of a patient,
comprising a valve assembly adapted to attach to an airflow
generator, the valve assembly having two ends, an inlet and an
outlet defined between each of the ends, and an interior. The valve
assembly further includes a motor means such as a solenoid which is
disposed at one of the ends, and an exit tube is defined at the
other of the ends. Next a valve seal within the interior connects
to and is operable by the motor means, the valve seal adapted to
cycle within the interior and across the inlet or outlet. A
controller circuit is then connected to the motor means for
operating the solenoid incrementally. Therefore, upon activation of
both the airflow generator and the controller circuit, pressurized
air from the airflow generator continuously enters the inlet but
passes out of the outlet only when the solenoid triggered by a flow
sensor activates the valve seal to at least partially unblock the
inlet such that the pressurized air is converted into a single,
repeatable burst of air exiting the outlet. The valve seals can be
configured in a variety of ways as long as some form of wall or
solid end acts as a seal and a defined slot or opening allows
airflow to incrementally pass out of the tube valve seal to thereby
modify the traditional, constant airflow.
[0015] The associated method then for modifying airflow into a
nasopharyngeal airway or trachea of a patient, comprises the steps
of producing a constant head of pressurized airflow into a valve
assembly attached to a patient via an air or gas tube, the valve
assembly including a mid-operated valve seal and flow sensor;
maintaining against the valve while the patient is exhaling and the
valve is at rest, and, permitting the valve to incrementally
retract and allow the airflow to pass through the valve assembly
and into nasopharyngeal airway or trachea when the patient inhales,
as a result converting the constant head of pressurized airflow
into an assisted burst of gas given during inhalation while
allowing the patient to finish inspiration and exhale against
little or no pressure when the valve is at rest.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 shows a schematic representation and partial
elevational view of the instant invention.
[0017] FIG. 2 shows an elevational view in partial section
illustrating an alternative embodiment of the valve of the present
invention.
[0018] FIGS. 3 and 4 show elevational views in vertical section
illustrating further embodiments of the apparatus valve of the
present invention.
[0019] FIG. 5 shows an elevational view in vertical section
illustrating still another alternative form of the system.
[0020] FIG. 6 shows perspective views of certain components
intended for other valve embodiments.
[0021] Dotted line arrows are shown to depict the direction of
patient exhaled breath flow. Solid line arrows mark the air stream
flow path of air drawn into the apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] The invention will now be described in detail in relation to
a preferred embodiment and implementation thereof which is
exemplary in nature and descriptively specific as disclosed. As is
customary, it will be understood that no limitation of the scope of
the invention is thereby intended. The invention encompasses such
alterations and further modifications and applications as would
normally occur to persons skilled in the art to which the invention
relates. This detailed description of this invention is not meant
to limit the invention, but is meant to provide a detailed
disclosure of the best mode of practicing the invention.
[0023] With reference then to FIGS. 1-6, illustrated is an assembly
10 which includes valve assembly 16, a programmable controller
circuit 12 encoded by programmer 8, a normally-open electrical
switch/sensor 18, and a patient interface device 20 such as a mask,
tracheal tube, nasal cannula or similar patient interface, and an
optional drug delivery port 19.
[0024] Valve assembly 16 has two ends 16c, 16d, an inlet 16a, an
outlet 16b, and an interior feed tube 7. Valve assembly 16 further
includes an electromagnetic solenoid 14 typically disposed
proximate end 16e, opposite exit tube 4, which is defined at end
16d. Instead of a solenoid 14 any type of motor means may be
implemented such a stepping motor. Motor means as used herein
therefore encompasses any type of motor, but preferably a solenoid
14.
[0025] The airflow generator 9, which is separate from and later
attached to the device, may be in the form of a blower or fan of
the type used to produce a pressurized airflow, hospital wall air
or compressed bottled air or gas. Airflow generator or airflow
generator means therefore is used herein to define any type of
blower, fan, hospital wall air, compressed air, or any traditional
positive airway pressure (PAP) device, including oxygen, already
attached to the same. The solid line arrows mark the air stream
flow path, beginning with air drawn into the apparatus from the
airflow generator 9 as indicated by arrow 22.
[0026] The electric current to operate the apparatus is supplied
through conductors 24 and 26, which also supply current to solenoid
14 and switch 18. The airflow generator 9 is intended to operate
continuously whereby a constant head of pressurized air is
maintained. However, the solenoid 14 is at rest and will permit
full air passage there through to the valve assembly 16 only when
the solenoid 14 is charged by switch 18.
[0027] The valve assembly 16 of FIG. 1 further includes a flexible
or rigid valve seal 28 such as a circular disc, ball or joined
split ball, with the flexible valve mounted to the plunger rod 11
of solenoid 14 plunger rod 11. In alternate, the use of a slotted
tube within two additional separated tubes may act as a valve (not
shown). Valve seal 28 is preferably seated within the interior feed
tube 7 and is operable by solenoid 14, adapted to cycle within the
feed tube 7 between solenoid 14 and exit tube 4, across outlet 166.
Valve seal 28 can alternatively be placed directly within exit tube
4, which would place valve seal 28 more proximate to end 16c, so
use of "within feed tube 7" is meant to encompass any location
throughout the interior of valve assembly 16 since exit tube 7 is
formed within the interior of valve assembly 16. In its relaxed
position (shown), the valve seal 28 will at least partially cover
and seal the outlet 16b or aperture of the therapy airflow or end
16d of the exit tube. The valve seal 28, in this case, is a member
which normally seals against the inside surface of the feed tube 7
but will open in response to airflow passing the switch (an attempt
to inhale) which signals solenoid 14 to charge (not shown) and seal
against the exit tube 4 which allows the airflow to pass through
the valve arrangement out of outlet 16b, the switch and thence into
the patient via a patient interface device 20. "Member" as used
herein can mean any shape, e.g. circular, square, etc. depending on
the inside surface of the feed tube 7 as long as the seal closes
against the feed tube 7.
[0028] It should be noted that the patient interface 20 and valve
assembly 16 will allo unassisted inhalation and exhalation by the
patient to permit entry of ambient air when the valve is in the "at
rest" position. The patient interface 20 is meant to be worn in
sealed relation to a patient whereby ambient air during inhalation
will pass into the patient interface past valve seal 28. Exhaled
breath will pass through switch 18 whereby the breath flow will be
in the direction of the dotted line arrow 38, and into the valve
assembly 16. Exhaled breath pressure entering the valve assembly 16
passes by the valve seal 28 which is now closed and seated against
the feed tube 7, and through exit tube 4 to ambient. A return
spring 40 allows the solenoid plunger rod 11 to return to its
original position upstream from said outlet 16b (towards inlet
16a). This return action of the solenoid sets the switch internally
whereby, as the solenoid 14 relaxes, the valve seal 28 will return
back to its original position and at the same time close off the
release of pressurized air or gas to complete the electrical
circuit to the solenoid 14. The solenoid 14 is thereby caused to
cycle open and then re-close after having permitted a "burst" of
pressurized air to move into the valve assembly 16 and past the
valve seal 28 out of outlet 16b and past the switch 18 and into the
patient interface 20. The pressurized airflow burst is directed
into the nasopharyngeal airway or trachea of the patient as the
patient's inhalation action occurs, and ambient air moves through
valve 16 to allow the patient to complete the breath intake
voluntarily. The subsequent exhalation by the patient repeats the
described process whereby a pulse, burst of pressurized air is
delivered to the patient interface 20 and thence to the patient's
airway as a function of each breathing cycle. An additional feature
triggers the pressurized gas flow by way of an adjustable timing
device should the patient not attempt to inhale himself. It should
be understood that "burst" used herein and in the claims refers to
a burst or flow of air of any duration and degree. For example, the
produced burst can emulate that of an MPAP, or Metered Positive
Airway Pressure device, wherein the burst terminates and slowly
dissipates in pressure. The burst an also emulate that of a
bi-level design wherein the burst has two levels of constant
pressure, namely a higher level of constant therapeutic pressure
upon inhalation along with a constant lower level of therapeutic
pressure upon exhalation.
[0029] The pressurized airflow burst is adjustable by way of the
controller circuit 12 which is encoded by way of the programmer 8.
The adjustments include, but are not limited to, ramp up time,
length of burst, sensitivity of the switch/sensor, timed release of
burst or any combination of these settings, should they be
required. The programmer 8 is linked to the control circuit by way
of a cable 3 which is rigidly connected to the programmer 8 but
which is detachable from the control circuit 12. Once the preferred
settings have been programmed into the control circuit they will
remain fixed until changed by reconnecting the programming box 8
and the settings are adjusted to alternate values. The values
appear on a viewing screen 6 nod are sot via a navigation button 5.
An additional embodiment allows the programmer 8 and control
circuit 12 to be combined into a single enclosure or with cable 3
rigidly connected to both the program box and the control circuit
12 for hospital use, EMS use, testing, etc. The valve assembly 10
is attached to a traditional CPAP unit or traditional constant
airflow generator 9 as above, which will convert that traditional
CPAP unit or traditional airflow generator into a device providing
an intermittent and adjustable air stream (gas), into a therapeutic
burst, puff, bolus or flow of air to a patient during inhalation.
By this means the patient is able to receive an air supply or
concentration of gas, given as a single, but repeatable dose to
achieve an immediate effect in transit through assembly 10 and by
way of patient interface 20. The system and method thus can be
utilized with pre-existing airflow generation means already
implemented in homes, centers and hospitals, thereby varying the
traditional constant airflow with use of the instant accessory. An
assisted burst of gas given during inhalation or inspiration at the
beginning of each breath will prevent collapse or maintain the
upper airway, reduce inspiratory WOB (work of breathing), reduce
expiratory WOB and reduce or prevent the dryness related to
continuous positive airway pressure. The assisted burst itself
raises the concentration in the body to a therapeutic level while
allowing comfort to the patient. This is accomplished to allow the
patient to finish inspiration himself and to exhale against little
or no therapeutic pressure. The bolus provided is adjustable and
tapers off over a period of time during the inspiration cycle, thus
allowing it to maintain positive pressure throughout most of the
inhalation process which will promote gas exchange in the alveoli
and also keep open smaller airways. A certain amount of natural
resistance experienced upon exhale through the exhalation circuit.
There may be times when a greater or therapeutic pressure upon
exhale is desired or required, the use of devices such as a
positive end-expiratory pressure (PEEP) valve may be added to tube
4 or by the addition of a similar restrictive device being
incorporated or added into the breathing circuit. As above, should
it be desirable, a continuous therapeutic flow of positive pressure
air upon inhalation along with a lower level of therapeutic
positive pressure airflow during exhalation could result.
[0030] In some cases additional medication is required. The
installation of the optional drug delivery port 19 allows the
introduction of inhalable medication. Because of the assembly 10
configuration, the delivery port can be added instantly without
harm to the patient or alternatively it can be applied initially
and with the entry port 21 being capped until needed.
[0031] As opposed to CPAP or continuous ventilation this method
allows an infinite control of therapeutic air or gas flow during
non invasive ventilation which is critical, especially in neonates.
Assembly 10 provides the clinician a means of providing safety and
comfort for those who cannot speak for themselves.
[0032] Although FIG. 1 broadly illustrates the underlying system
and method of the present invention, the use of different valves,
sensors and components are possible. In lieu of solenoid 14 a
stepping motor or similar control (not shown) may be used to
control the pressurized air/gas delivery by rotating a seal within
valve assembly 16. However, additional components similar to those
shown in FIG. 2 would be required.
[0033] FIG. 2 shows a sliding tube valve seal 17, whereby it
replaces the above mentioned valve seal 28 with a slotted, hollow
tube. The sliding tube valve seal 17 is connected to the solenoid
valve 14 by way of plunger rod 11 and closes off air pressure when
the solenoid 14 is relaxed as shown. At least one slot 17a is
defined within the outer shell of the hollow tube. A seal or wall
15 positioned beyond slot 17a and within the sliding tube valve
seal 17 directs the flow of air to the patient when the tube is
pushed forward by the solenoid valve. In addition, the sliding tube
valve seal 17 directs the flow of exhaled air from the patient
through exit tube 4 to atmosphere. An additional hole or exhalation
slot 17b or other means to allow the exhaled air to re-enter the
hollow tube and proceed to exit tube 4 is defined on the other side
of wall 15. The placement of the slots 17a, 17b in the tube may be
adjustable or fixed in order to control both the inhalation and
exhalation pressures. The sliding tube valve seal 17 slides freely
within the feed tube 7 and exit tube 4 and is controlled by way of
the solenoid 14.
[0034] In alternate, a second method and device for converting a
constant airflow generator to a multi-level therapeutic device by
way of assembly 10 attached to a CPAP unit or traditional constant
airflow generator, 12 will convert a traditional CPAP unit or
traditional airflow generator into a device providing an adjustable
air stream or gas, into multiple pressurized therapeutic air flows
and delivering them to a patient.
[0035] The device is able to deliver bi-level or multiple levels of
therapeutic flows of air or gas to a patient. A patient may receive
one or more levels of pressurized air upon inhalation and one or
more lower levels of pressurized air upon exhalation. This may be
accomplished in several ways such as by leaving valve 28 open or
partially open at all times and regulating the distance between
valve 28 and feed tube 7 during inhalation. Thus one or more
elevated pressures is delivered to patient through assembly valve
16, switch 18 and patient interface 20 upon inhalation while
bleeding off the excess air and pressure through tube 4. The valve
28 would then partially adjust to a predetermined position or
predetermined positions for exhale creating a lower exhalation
pressure or multiple lower exhalation pressures. This could allow a
bleed off of air by way of tube 4. Although not necessary, for a
split second valve 28 could close against feed tube 7 and start the
cycle over or the-add on device could just switch back to the
higher level upon inhalation.
[0036] As a third method and device, seal 28 could close off or
partially close off against tube 4 during inhalation and then open
the exit port for exhalation to release a predetermined amount of
air flow and pressurized air to cause the required pressure drop.
The process would then repeat itself as described previously.
[0037] FIG. 3 and FIG. 4 illustrate smaller versions of the
assembly 16 in that the airflow is controlled in a straight tube
and components are more compact.
[0038] FIG. 5 shows a fourth method and device wherein the return
spring 40 may be positioned between the solenoid 14 and valve seal
28 and will be of sufficient strength to control the flow of air or
gas coming from the constant air flow generator. In this embodiment
the spring is compressed when the solenoid 14 is charged allowing
the air flow and pressure to increase to a therapeutic level. When
the solenoid 14 is at rest the air flow is restricted to a lower
level or may be shut off completely. Ventilation holes 33 or slots,
allow exhalation of the patient and provide ambient air should a
power failure occur. In addition, these ventilation holes 33 may be
restricted or sealed in order to regulate inhalation and/or
exhalation pressure. As an alternate, (not shown) the return spring
may be positioned within the solenoid itself between the back end
of the solenoid and the tip of the plunger 11. Accordingly,
"attached to" as used in relation to the spring and solenoid means
the spring can be attached to the exterior of the solenoid or be
integrated within the solenoid. As previously stated seal 28 could
close off or partially close off against tube 4 during inhalation
and then increase open the exit port for exhalation to release a
predetermined amount of air flow and pressurized air to cause the
required pressure drop. The process would then repeat itself as
described previously.
[0039] In any of the apparatuses and methods above, the use of
sliding tube valve seal 17 (slotted tube of FIG. 2) in place of the
seal 28 is possible. Furthermore, with reference to FIG. 6, several
controlling configurations as shown may be used in place of the
sliding tube valve seal 17 in FIG. 2 or in place of valve seal 28
on FIG. 5. Any of the valve seals can be keyed by use of a slot 34
and guide. The guide may be a pin, key, roller or any variation of
these. Accordingly, "tube valve seal" as defined herein means any
shape of tube shown and described above and by the alternative
embodiments of FIG. 6 and their obvious variations, the critical
feature of which require some form of wall 28 or solid end to act
as a seal and a defined slot 17a (FIG. 2) opening to allow airflow
to pass out of the tube valve seal. As in the first method the
valve seal 28 can be a circular soft or rigid member which normally
seals against the inside surface of the feed tube 16 on FIG. 5. The
seal mates against or close to the face of a now split or two piece
tube (not shown) but will respond to airflow passing the switch (an
attempt to inhale) which signals solenoid 31 to charge (not shown)
which allows the airflow to pass through the valve arrangement out
of outlet 16b, the switch 18 and thence into the patient via a
patient interface device 20. In alternate, solenoid 14 may also be
made to respond to exhalation when continuous airflow during
inhalation is present. In such a case valve 28 is will regulate the
airflow in relation to exit tube 4.
[0040] In the above embodiments the valve seal and tube valve seal
move laterally within or against the feed tube (or the exit tube).
It should be understood that another seal embodiment may be a
butterfly valve intended to accomplish the same results, however in
this embodiment the valve would move a quarter-turn rotationally.
Therefore, in either instance of the valve seal, tube valve seal,
or butterfly valve, as used in the claims, the valve will cycle
back and forth in relation to the outlet and exit tube and "cycle"
either laterally or rotationally.
* * * * *